Marquette receives a proposal from an outside contractor who offers to make and ship $1,500$ fences directly to Marquette$$s customers as orders arrive from Marquette$$s sales force. When managers meet to discuss this proposal, Product Manager Will Hansen brings up the fact that they have the design for an electric fence that can be used for large animals that have never been produced. Will suggests that this may be the perfect time to launch this new product and at a selling price of $$225$ per unit it is sure to increase sales revenue. The production manager calculates that the idle time created by accepting the contractor's offer would allow them to produce $1,000$ of the new fence. The cost to produce the new fence would be $$175$ in variable manufacturing expense but fixed manufacturing and marketing costs would remain unchanged. The product mix would now be $1,000$ of the new fence and $1,500$ of the old fence. If Marquette wants to seriously consider taking the contractors offer, what in$-$house cost should be used to evaluate the outside contractor$$s bid. If the payment to the outside contractor is $$90$ per unit, should they accept the offer? Why or why not?